TOLTERODINE TARTRATE
Clinical safety rating: safe
Strong CYP3A4 inhibitors may increase levels Can cause blurred vision and urinary retention.
Competitive antagonist of muscarinic acetylcholine receptors (M1, M2, M3, M4, M5) with relative selectivity for the bladder over salivary glands. Reduces detrusor muscle contractility and bladder pressure.
| Metabolism | Hepatic via CYP2D6 (major) and CYP3A4 (minor); active metabolite 5-hydroxymethyl tolterodine (DD01) is equipotent. Poor metabolizers (CYP2D6 poor metabolizers) have higher exposure via CYP3A4. |
| Excretion | Renal (77%) and fecal (17%): approximately 14% as unchanged tolterodine, 51% as the active 5-hydroxymethyl metabolite, and 12% as other metabolites. Biliary excretion contributes minimally. |
| Half-life | Terminal elimination half-life is 2-3 hours in extensive metabolizers (CYP2D6) and approximately 9 hours in poor metabolizers. In clinical context, dosing interval is adjusted in poor metabolizers (e.g., 2 mg twice daily reduced to 2 mg once daily). |
| Protein binding | Approximately 96.3% bound to plasma proteins, primarily to alpha-1-acid glycoprotein (orosomucoid). |
| Volume of Distribution | 1.4 L/kg (range 1.0-1.9 L/kg), indicating extensive extravascular distribution and moderate tissue penetration. |
| Bioavailability | Oral: absolute bioavailability of tolterodine is approximately 17% in extensive metabolizers due to extensive first-pass metabolism. In poor metabolizers, bioavailability is higher (up to 65%) due to reduced CYP2D6 activity. |
| Onset of Action | Oral: clinical effect (reduction in urinary frequency) typically observed within 1-2 hours after administration. |
| Duration of Action | Oral: lasts approximately 8-12 hours, supporting twice-daily dosing. Clinical effect may persist longer in poor metabolizers due to prolonged exposure. |
2 mg orally twice daily. May be reduced to 1 mg orally twice daily based on tolerability.
| Dosage form | CAPSULE, EXTENDED RELEASE |
| Renal impairment | For GFR 30-80 mL/min: no adjustment. For GFR <30 mL/min: 1 mg orally twice daily. |
| Liver impairment | Child-Pugh class A or B: 1 mg orally twice daily. Child-Pugh class C: not recommended. |
| Pediatric use | Not approved for use in pediatric patients (safety and efficacy not established). |
| Geriatric use | Consider starting at 1 mg orally twice daily due to increased sensitivity; titrate based on response and tolerability. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Strong CYP3A4 inhibitors may increase levels Can cause blurred vision and urinary retention.
| FDA category | Animal |
| Breastfeeding | Excretion into human milk is unknown. The M/P ratio has not been determined. Tolterodine and its metabolite (DD01) are excreted in milk of lactating rats at concentrations higher than plasma. Caution advised; avoid breastfeeding or use alternative therapy. |
| Teratogenic Risk | Pregnancy Category C. No adequate and well-controlled studies in pregnant women. In animal studies, tolterodine caused embryo-fetal lethality and decreased fetal weight at doses 20 times the human AUC at the MRHD (4 mg/day). First trimester: Potential risk cannot be ruled out; use only if benefit outweighs risk. Second and third trimesters: Limited data; theoretical risk due to anticholinergic effects on fetal GI motility and heart rate. |
■ FDA Black Box Warning
None
| Common Effects | Dry mouth |
| Serious Effects |
["Urinary retention","Gastric retention","Uncontrolled narrow-angle glaucoma","Hypersensitivity to tolterodine or any component","Severe hepatic impairment"]
| Precautions | ["Urinary retention","Gastric retention","Narrow-angle glaucoma","QT prolongation (dose-related)","Hepatic impairment (dose reduction in moderate impairment; not recommended in severe)"] |
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| Fetal Monitoring | Monitor maternal heart rate and blood pressure for anticholinergic effects (tachycardia, hypertension). Assess fetal heart rate and uterine activity if used near term due to potential for fetal tachycardia. Monitor for urinary retention and constipation in mother. |
| Fertility Effects | No human data on fertility. In animal studies, no impairment of fertility was observed in male and female rats at doses up to 2 mg/kg/day (approximately 5 times the human AUC at MRHD). However, anticholinergic effects may theoretically affect reproductive function. |